A/C Spruce has it on page 323 called: "Torque Seal". or "Skydrol". Both
are called inspection lacquers. In the past we used a yellow 3M
weatherstrip adhesive on racing dirt bikes. It actually holds the nut to
the bolt and not just a movement indicator.
Stu Fields Safari driver
"Eugene Wendland" wrote in message
...
Does anyone know what compound is used to secure the nuts and threads on
aviation engines? I'm not talking about loctite, but the compound that is
placed on the outside of the nut and then onto the threads. Usually, it's
a
very visible colour and laid in a straight line so that one can visually
see
if a nut or bolt has backed off. I've seen it done with silicon, but I'm
wondering what the real hard compound is. Any suggestions?

Thanks

Gene